Biology Faculty Articles
Title
A Confirmatory Test for Sperm in Sexual Assault Samples Using a Microfluidic Integrated Cell Phone Imaging System
Document Type
Article
Publication Date
9-1-2020
Publication Title
Forensic Science International: Genetics
Keywords
Sexual assault, Screening, Sperm identification, Computer vision, Cellphone imaging, Microfluidics
ISSN
1872-4973
Volume
48
First Page
102313
Abstract
Rapid and efficient processing of sexual assault evidence to accelerate forensic investigation and decrease casework backlogs is urgently needed. Therefore, the standardized protocols currently used in forensic laboratories can benefit from continued innovation to handle the increasing number and complexity of samples being submitted to forensic labs. To our knowledge, there is currently no available rapid and portable forensic screening technology based on a confirmatory test for sperm identification in a sexual assault kit. Here, we present a novel forensic sample screening tool, i.e., a microchip integrated with a portable cell phone imaging platform that records and processes images for further investigation and storage. The platform (i) precisely and rapidly screens swab samples (<15 min after sample preparation on-chip); (ii) selectively captures sperm from mock sexual assault samples using a novel and previously published SLeX-based surface chemistry treatment (iii) separates non-sperm contents (epithelial cells and debris in this case) out of the channel by flow prior to imaging; (iv) captures cell phone images on a portable cellphone-integrated imaging platform, (v) quantitatively differentiates sperm cells from epithelial cells, using a morphology detection code that leverages Laplacian of Gaussian and Hough gradient transform methods; (vi) is sensitive within a forensic cut-off (>95% accuracy) compared to the manual counts; (vii) provides a cost-effective and timely solution to a problem which in the past has taken a great deal of time; and (viii) handles small volumes of sample (20 μL). This integration of the cellphone imaging platform and cell recognition algorithms with disposable microchips can be a new direction toward a direct visual test to screen and differentiate sperm from epithelial cell types in forensic samples for a crime laboratory scenario. With further development, this integrated platform could assist a sexual assault nurse examiner (SANE) in a hospital or sexual assault treatment center facility to flag sperm-containing samples prior to further downstream testing.
Additional Comments
National Institute of Justice award #: 2017-NE-BX-0004
NSUWorks Citation
Deshmukh, Shreya; Fatih Inci; Merve Goksin Karaaslan; Mehmet Giray Ogut; Derek Duncan; Leonard Klevan; George Duncan; and Utkan Demirci. 2020. "A Confirmatory Test for Sperm in Sexual Assault Samples Using a Microfluidic Integrated Cell Phone Imaging System." Forensic Science International: Genetics 48, (): 102313. doi:10.1016/j.fsigen.2020.102313.
ORCID ID
0000-0002-4931-5316
DOI
10.1016/j.fsigen.2020.102313
Comments
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